Question C7 HP

[Fast Freddie]

Hey guys, new member here I purchased a 2017 GS about 5 weeks ago and was looking to get just a little more power. I have taken it to Race ready garage in Cambridge as I have heard lots of good things. Anyone have a idea on what I can expect for rwhp with headers x pipe and tune ?

 

[Rruuff Day]

Hey guys, new member here I purchased a 2017 GS about 5 weeks ago and was looking to get just a little more power. I have taken it to Race ready garage in Cambridge as I have heard lots of good things. Anyone have a idea on what I can expect for rwhp with headers x pipe and tune ?

For what my estimates are worth (but they have been pretty close in the past) I'm guessing you should be around 428 at the rear wheels with those mods. Cambridge is about 1000 feet above sea level so about 3% loss from a sea level dyno run. My guess stock would be about 390 so call it a solid 10% rear wheel gain.

 

[tyho]

I agree ... about 430 at the rear wheels. Add 15-18% to get to the crank, depending on auto or manual. OEM is about 400 at the rear wheels so 460 at the crank.

 

[Fast Freddie]

For what my estimates are worth (but they have been pretty close in the past) I'm guessing you should be around 428 at the rear wheels with those mods. Cambridge is about 1000 feet above sea level so about 3% loss from a sea level dyno run. My guess stock would be about 390 so call it a solid 10% rear wheel gain.

Thank you assuming torque is about the same increase as HP ?

 

[Rruuff Day]

Thank you assuming torque is about the same increase as HP ?

The LT1 has a great torque curve from start to finish. Certainty something GM did well as these engines really pull. I would expect 417 lb-ft or so for torque at the wheels so, no. It doesn't chase horsepower at quite the same increase rate. Torque peaks quite a bit earlier than horsepower but the C7 stock has a pretty flat curve. It stays well ahead of horsepower at a very hot 365 lb-ft at 2000 rpm ramping up from there to about 400 lb-ft or so at it's peak at 5200 rpm. The torque curve starts to drop from there and meets the horsepower still rising (albeit slower) at about 5900 rpm, and about 390 HP. These numbers are only estimates as each car's engine and drive train is somewhat unique but fear not. You will certainly feel the difference. Be sure to let us know the results when you get your baby back...... and we like pictures too.

 

[Fast Freddie]

You guys were very close 428 rwhp at 5800 and 425 Torque at 4100... very please very nice guys at race ready Garage

 

[Rruuff Day]

You guys were very close 428 rwhp at 5800 and 425 Torque at 4100... very please very nice guys at race ready Garage

4100 is early for the torque peak. I'm suspecting it stays relatively flat up closer to 5100 before it starts to dive. Wouldn't mind seeing the graph if you'd be so kind as to post a picture. Thanks.

 

[Fast Freddie]

Here is the graph

 

[Rruuff Day]

Here is the graph

Thanks. Exactly what I expected. The torque damn near holds flat at peak all the way to 5100 and actually continues to pull pretty damn hard right to redline... So. Are you happy with the extra power? What you hoped for?

 

[tyho]

Nice. You should be around 495 at the crank. A good solid 35 hp gain. The biggest noticeable gain I had was when I changed to a Halltech cai. The car already had headers but no tune. Despite what many say that a cai will not give you much hp gain, I noticed a difference the moment I pulled out of Dave's shop. Enjoy your ride.

 

[Fast Freddie]

Thanks guys I am very happy with the results car seems to really pull, I will know better in the spring unfortunately it will probably go away till spring. With cold roads and tires it was breaking loose quite easy, but I loved it... lol will know even more with some dry warm roads next spring ...cheers